If you get a year in a cell, your browser does not
claim to support the DOM module for a given DOM Level. The year
in the cell is the year of the release of the W3C DOM
Recommendation that defines the DOM module.

test all DOM implementations available in your user agent if
more than one are available;
It only tests the DOM implementation directly available from the
document displayed, i.e. this page.

check your user agent claims.
To check if your user agent really implements a DOM module and
does not only claim to, use the DOM Conformance
Test Suites available from http://www.w3.org/DOM/Test.

Note: The XML and HTML modules require to have support for
the core methods. With DOM Level 2, a DOM can implement the core
methods separatly and claim support for the Core module. With Level
1, there is no Core module but core methods must still be
supported with DOM Level 1 XML and HTML.

How does this page work?

This page uses primarily the W3C DOM Level 1 Recommendation and
relies on the XHTML 1.0 handling in your user agent. The contents
inside the table is changed via a script using the DOM Level 1
core methods which must be supported by any user agent that claims
to support DOM. Colors are also changed using methods defined in
the DOM Level 2 CSS2 module and, given that this module was
defined to be backward compatible with existing practices, you may
see changes in the colors even if the DOM implementation does not
claim to support the DOM Level 2 CSS2 module, or does not support
the DOM Level 1 core methods properly.

The script is
available at http://www.w3.org/2003/02/06-dom-support-js.js.

Note: This page is served using the media type
application/xhtml+xml and uses the W3C XHTML 1.0
Recommendation. The style sheets are served using the media type
text/css and use the W3C CSS1 Recommendation. The
script is served using the unregistered media type
application/x-javascript and uses the ECMA-262 and
W3C DOM specifications. An HTML 4.01
version of this page is available at
http://www.w3.org/2003/02/06-dom-support.html. You can also test
support for alternative
DOM modules.